We know it’s a common misconception, but it’s actually impossible to turn fat into muscle, or vice versa. They are completely different, and you can’t turn one into the other. If you are looking to either lose body fat or gain muscle, your weight is going to have to change in some way. Both fat and muscle have weight to them.
Just like anything else though, you simply just can’t transform one thing into another. You can, however, lose fat and then gain muscle, or do it in reverse order. The end result there is that you would be a similar weight with a higher percentage of muscle and lower percentage off at. This would, of course, be a very slow process altogether, as well.